Burn no doubt that God will use anything and anyone to spread the gospel. I certainly didn't come to believe in the Lord by just reading the KJV. That doesn't mean that it is still not extremely important for doctrinal reasons to determine exactly what God said.
Besides, there is not a single doctrinal difference between the TR and the newer master texts. Not one.
Have you researched this out? From what I seen in my studies, a variety of influences are at work on MB's that make them inferior to the KJV, doctrinally.
Let's take one example that we're all familiar with and all suffered quite a bit from it's doctrinally inferior form:
Matthew 24: 45
KJV - Who then is a faithful and wise servant, whom his lord hath made ruler over his household, to give them meat in due season?
NIV - "Who then is the faithful and wise servant, whom the master has put in charge of the servants in his household to give them their food at the proper time?
NASB - "Who then is the faithful and sensible slave whom his master put in charge of his household to give them their food at the proper time?
Jewish Bible - "Who is the faithful and sensible servant whose master puts him in charge of the household staff, to give them their food at the proper time?
RS - "Who then is the faithful and wise servant, whom his master has set over his household, to give them their food at the proper time?
NWT - “Who really is the faithful and discreet slave whom his master appointed over his domestics, to give them their food at the proper time?
Now I don't know exactly why the King James Version uses the indefinite article 'a" as opposed to the definite article "the" here. But the fact is that they did. Perhaps because there is no definite article in the Greek they consulted an early different language copy that did contain the indefinite article. I don't know....haven't researched it out.
What I do know is that my mother and father hang onto this scripture for dear life and at the behest of the WT, have determined that their salvation is dependent on finding the one religion (instead of Christ) who really is THE faithful and discreet salve. Possibly, they ( and previously us) would not have followed a cult had we read 'a" faithful and discreet slave, or at least less apt to.
The RSV was largely Wescott's and Hort's doing from my understanding. I can just see 'ole Russell scratching his white beard reading it. And, in all his eccentricity thinking, maybe, just maybe..... I'm the Faithful and Wise Servant foretold from long ago. Later, his cronies certainly claimed that title for themselves and made themselves an anti-christ.
The rest is history.